1. Field of the Invention
The present invention relates to a backlight module and a display apparatus thereof, and more specifically, to a backlight module of disposing a phosphor layer structure between a light entrance surface of a light guide plate and a backlight source and away from the backlight source by a specific distance and a display apparatus thereof.
2. Description of the Prior Art
Since liquid crystal molecules do not produce light themselves, a common method for driving a liquid crystal display device to display images involves utilizing a backlight module to provide light with sufficient brightness and uniform distribution to the liquid crystal display device. Therefore, a backlight module is one of the major components of a liquid crystal display device.
A conventional light emitting design is to utilize an LED (Light Emitting Diode) device disposed on a light emitting side of a light guide plate to emit white light into the light guide plate and then generate a surface light source with sufficient brightness and uniform distribution via the light guiding design of the light guide plate.
The aforesaid LED device for generating the white light usually utilizes a design of packaging an LED for emitting light of a specific wavelength and a silica gel doped with corresponding phosphors, so as to generate the white light when the phosphors are excited by light emitted from the LED (e.g. utilizing a blue LED to excite yellow phosphors, utilizing a blue LED to excite dual-color phosphors, or utilizing an ultraviolet LED to excite red, green, and blue phosphors).
However, since heat energy generated by the LED could be directly transmitted to the phosphors in the aforesaid design, thermal degradation of the phosphors may occur after the LED device is used over a period of time, so as to influence the gray tone and color coordinate of the white light. Thus, the aforesaid design may not only reduce the image display quality of the liquid crystal panel, but also decrease the light emitting efficiency and life of the phosphors.